Patent GB-191318673-A (GB)
Title: Improved Arrangements for Exciting Rontgen Ray Tubes.
IPC: H05G1/22
Filed: 1913-08-16
Granted: 1914-07-16
Abstract: 18,673. Siemens Bros. & Co., [Siemens & Halske Akt.-Ges.]. Aug. 16. R÷ntgen-ray apparatus.-For obtaining instantaneous p h o t ographs by R÷ntgenrays, means are described by which, for a single exposure, the secondary voltage of a transformer energized by an alternating current is impressed on the tube for approximately the duration of a single period or less of the alternating current. To obtain the best effect, the primary circuit is closed at the moment when the e voltage through the supply mains is passing through zero value, and is opened again when the induction is at its maximum value. The means described are also adapted for kinematograph exposures. In one apparatus, the primary circuit includes a time-switch z, Fig. 1, which is closed by hand, and a rapidly rotated interrupter with a contact-segment s. The time-switch breaks the primary circuit within the interval of one complete revolution of the interrupter u, and by adjusting the segment s to the fraction of the interval during which the primary circuit is closed, the exposure can be made to correspond to a single period or less of the alternating- current cycle. A time-fuse s<1>, Fig. 3, may be substituted for the time-switch, and in order to complete the secondary circuit for any particular interval of and at any particular phase of the alternating current, a high-tension interrupter with contact-arms c', c<2> and contactsegments a<1>, a<2>, b<1>, b<2> may be used. These contact-segments may be adjustable in length and disposition. In lieu of an interrupter, a high-tension rectifier may be used, so that the discharge through the tube may be in the same direction during the whole period of the alternating current. For kinematograph exposures, a contact-apparatus, such as that shown in Fig. 3, is rotated synchronously with the alternating current and connects the secondary terminals of the transformer and the electrodes of the Rontgen-ray tube for a half-period and repeats this connexion with intervals of rest which are odd multiples of a half - period. Alternatively, the primary circuit of the transformer may be periodically closed for the duration of a period of the alternating current, by an arrangement such as that shown in Fig. 1, while by means of a synchronously rotating device, such as is shown in Fig. 3, or by a rectifier, the R÷ntgen-ray tube is energized in known manner, by current impulses from the same circuit, which are always in the same direction. The time-switch z can be adjusted to allow as many exposures as are required. In a device for closing the primary circuit at the zero or any phase of the primary current and for any interval, two insulated contactsegments i, j, Figs. 6 and 7, are relatively adjustable and are bridged by contact-brushes c mounted on a rotating arm a. The arm is loosely mounted on a shaft w and rotated by a spring f. In the position shown in Fig. 6, the arm a is held by the spring f against the armature c of an electro-magnet r carried on an arm t. This arm is adjusted by adjusting vertical arms which project through slots q in the cover p, and this also adjusts the position of other contacts x<1>, x<2>, y<1>, y<2>, which arc connected as shown in Fig. 7. On rotating the arm shaft w by the handle h, the arm d is rotated behind a spring catch k<2>, and the contact v makes contact with the contact y<2>, thereby closing the circuit containing the switch H and electro-magnet r. This action draws the armature c from the stop on the arm a, and contacts e rotate under the influence of the spring f. The brushes e complete the primary circuit for a period determined by the relative adjustment of the contacts i, j. The contact j is adjusted by gearing n. The movement of the arm a breaks the circuit through the electromagnet r, and the arm d has to be again rotated through 180 degrees to complete the circuit through the contacts y<1>, v, x<2>, u, and bringing the arm d behind the catch k<1>. A series of impulses can be obtained by continuously rotating the handle h, and the phase at which the primary circuit is completed is determined by the length of path travelled by the arm a rotating under the action of the spring f, and is adjusted by adjusting the position of the arm t relatively to the contacts i, j.